Oxidation of ferrous iron, Fe(II), to ferric iron, Fe(III), is an important reaction in drinking water
treatment and distribution systems, and the ferric particles that form are a major source of
consumer complaints about colored water. Ferrous iron is found naturally in many groundwaters
and can be released from distribution system materials. Bench-scale experiments were
conducted to study the effects of pH, oxidant type (oxygen, chlorine, and chlorine dioxide), and
oxidant concentration on the properties of Fe(III) particles and suspensions formed from Fe(II)
oxidation. The color and turbidity per unit mass of iron of suspensions formed from oxygen were
more than twice those of suspensions formed from chlorine and chlorine dioxide at all pH
values. Similar observations were made during tests with oxygen and chlorine using natural
groundwaters at two field locations. Particles formed from chlorine and chlorine dioxide were
less dense and had a greater capacity to adsorb orthophosphate. Experimental observations
were explained using a model that considers differences in Fe(III) particle formation and
growth pathways. These research findings have practical implications related to both water
treatment (iron removal) and distribution system issues. Includes 39 references, tables, figures.
| Edition : | Vol. 96 - No. 8 |
| File Size : | 1
file
, 1.5 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 08/01/2004 |
